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macsec: Detect if Rx skb is macsec-related for offloading devices that update md_dst

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Can now correctly identify where the packets should be delivered by using
md_dst or its absence on devices that provide it.

This detection is not possible without device drivers that update md_dst. A
fallback pattern should be used for supporting such device drivers. This
fallback mode causes multicast messages to be cloned to both the non-macsec
and macsec ports, independent of whether the multicast message received was
encrypted over MACsec or not. Other non-macsec traffic may also fail to be
handled correctly for devices in promiscuous mode.

Link: https://lore.kernel.org/netdev/ZULRxX9eIbFiVi7v@hog/
Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: stable@vger.kernel.org
Fixes: 860ead89b851 ("net/macsec: Add MACsec skb_metadata_dst Rx Data path support")
Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Reviewed-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://lore.kernel.org/r/20240423181319.115860-4-rrameshbabu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Rahul Rameshbabu 2024-04-23 11:13:04 -07:00 committed by Jakub Kicinski
parent 6e159fd653
commit 642c984dd0
1 changed files with 36 additions and 10 deletions
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46
drivers/net/macsec.c
View File

@ -999,10 +999,12 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
struct metadata_dst *md_dst;
struct macsec_rxh_data *rxd;
struct macsec_dev *macsec;
bool is_macsec_md_dst;
rcu_read_lock();
rxd = macsec_data_rcu(skb->dev);
md_dst = skb_metadata_dst(skb);
is_macsec_md_dst = md_dst && md_dst->type == METADATA_MACSEC;
list_for_each_entry_rcu(macsec, &rxd->secys, secys) {
struct sk_buff *nskb;
@ -1013,14 +1015,42 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
* the SecTAG, so we have to deduce which port to deliver to.
*/
if (macsec_is_offloaded(macsec) && netif_running(ndev)) {
struct macsec_rx_sc *rx_sc = NULL;
const struct macsec_ops *ops;
if (md_dst && md_dst->type == METADATA_MACSEC)
rx_sc = find_rx_sc(&macsec->secy, md_dst->u.macsec_info.sci);
ops = macsec_get_ops(macsec, NULL);
if (md_dst && md_dst->type == METADATA_MACSEC && !rx_sc)
if (ops->rx_uses_md_dst && !is_macsec_md_dst)
continue;
if (is_macsec_md_dst) {
struct macsec_rx_sc *rx_sc;
/* All drivers that implement MACsec offload
* support using skb metadata destinations must
* indicate that they do so.
*/
DEBUG_NET_WARN_ON_ONCE(!ops->rx_uses_md_dst);
rx_sc = find_rx_sc(&macsec->secy,
md_dst->u.macsec_info.sci);
if (!rx_sc)
continue;
/* device indicated macsec offload occurred */
skb->dev = ndev;
skb->pkt_type = PACKET_HOST;
eth_skb_pkt_type(skb, ndev);
ret = RX_HANDLER_ANOTHER;
goto out;
}
/* This datapath is insecure because it is unable to
* enforce isolation of broadcast/multicast traffic and
* unicast traffic with promiscuous mode on the macsec
* netdev. Since the core stack has no mechanism to
* check that the hardware did indeed receive MACsec
* traffic, it is possible that the response handling
* done by the MACsec port was to a plaintext packet.
* This violates the MACsec protocol standard.
*/
if (ether_addr_equal_64bits(hdr->h_dest,
ndev->dev_addr)) {
/* exact match, divert skb to this port */
@ -1036,14 +1066,10 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
break;
nskb->dev = ndev;
if (ether_addr_equal_64bits(hdr->h_dest,
ndev->broadcast))
nskb->pkt_type = PACKET_BROADCAST;
else
nskb->pkt_type = PACKET_MULTICAST;
eth_skb_pkt_type(nskb, ndev);
__netif_rx(nskb);
} else if (rx_sc || ndev->flags & IFF_PROMISC) {
} else if (ndev->flags & IFF_PROMISC) {
skb->dev = ndev;
skb->pkt_type = PACKET_HOST;
ret = RX_HANDLER_ANOTHER;